An end to the Gulf of Mexico oil disaster was in sight as BP plugged its runaway well and US officials said most of the toxic crude has been cleaned up or dispersed.
Though undoubtedly the best day since the disaster began more than 15 weeks ago, US officials cautioned that a great deal of clean-up work remained and that the long-term impact could be felt for years, even decades, to come.
BP's long-awaited "static kill" was conducted overnight as heavy drilling fluid was rammed into the busted Macondo well for eight hours, forcing the oil back down into the reservoir miles beneath the seabed.
We "have reached a static condition in the well that allows us to have high confidence that there will be no oil leaking into the environment," US spill response chief Thad Allen told reporters at a White House briefing.
|A Brown Pelican flies at the Pelican Harbor Seabird Station as the center prepares to transfer the birds after they were rehabilitated from the oil spill in the Gulf of Mexico in Florida.|
The breakthrough came 106 days after a devastating explosion aboard the BP-leased Deepwater Horizon rig on April 20 killed 11 workers and unleashed a torrent of oil into the Gulf.
"So, the long battle to stop the leak and contain the oil is finally close to coming to an end. And we are very pleased with that," US President Barack Obama said. "Our recovery efforts, though, will continue. We have to reverse the damage that's been done."
Allen later authorized BP to cement over the busted well, an operation that the British-based energy giant said would begin Thursday.
The US pointman also said, however, that he had "made it clear" to the company that the cementing should "in no way delay the completion of the relief well," expected to be finished mid-August to seal the well sealed permanently.
At 4.9 million barrels -- or enough oil to fill 311 Olympic-sized swimming pools -- the disaster is the biggest maritime spill on record.
It threatened the fish and wildlife-rich US Gulf coast with environmental ruin and plunged residents of coastal communities into months of anguish over their livelihoods and the region's future.
A government report released Wednesday found that a third of the oil was captured or mitigated through burning, skimming, chemical dispersion and direct recovery from the wellhead.
Heat from the sun helped some of the chemicals in the crude evaporate. Waves and currents broke the slick up into smaller patches. Then the microbes which feed on natural oil seeps in the Gulf got to work, it said.
"At least 50 percent of the oil that was released is now completely gone from the system," said Jane Lubchenco, head of the National Oceanic and Atmospheric Administration.
"And most of the remainder is degrading rapidly, or is being removed from the beaches."
But Lubchenco was quick to stress that scientists will not be able to determine for a long time the full extent of the damage.
"The oil that was released and has already impacted wildlife at the surface, young juvenile stages and eggs beneath the surface, will likely have very considerable impacts for years and possibly decades to come," she told reporters at the White House briefing.
The problem, she explained, is that oil is still toxic even when it has been broken down into very small droplets. And there was simply so very, very much of it.
About 24 percent of the Gulf's federal waters remain closed to fishing, and even when fishermen are able to fill their nets they fear consumers might not believe the seafood is safe to eat.
With tourists likely to avoid Gulf beaches for years and oil industry jobs under threat from Obama's moratorium on new deep sea drilling permits, the future remains bleak for many coastal communities.
BP, meanwhile, is hoping to rebuild its shattered reputation but must also meet the claims of thousands of individuals and businesses whose livelihoods have been washed away, while a mammoth civil trial looms.
BP senior vice president Kent Wells expressed relief that 20 days after the flow of oil in the sea was stemmed with a temporary cap "it's very difficult for us to find any oil anywhere on the surface."
He refused, however, to declare victory until the well is permanently sealed.